Characterization of strawberry cultivars for resistance to arthropod pests mediated by leaf trichomes

ABSTRACT Strawberry (Fragaria × ananassa) is a nutritionally rich pseudo-fruit valued for its distinctive flavor, aroma, and high antioxidant and mineral content. It is consumed both fresh and as an ingredient in various food products. However, strawberry crops are highly susceptible to arthropod pests, particularly the two-spotted spider mite (Tetranychus urticae) and the strawberry aphid (Chaetosiphon fragaefolii), often leading growers to rely heavily on chemical control, with associated environmental and health risks. Genetic resistance offers a sustainable alternative. Identifying potential parental lines with elevated resistance can support the development of new resistant cultivars. In this study, 41 strawberry genotypes from the State University of Londrina collection were evaluated for resistance in choice and no-choice bioassays against T. urticae and C. fragaefolii, and leaf trichomes (glandular and non-glandular) were quantified. Correlations between trichome densities and past performance were analyzed. Significant variability in pest resistance was observed among genotypes, primarily associated with glandular trichomes. The cultivars Camino Real, Ceres, and the experimental genotype RVDA44 exhibited the highest resistance, limiting pest oviposition, survival, and movement, and represent promising candidates for commercial cultivation and as parental lines in breeding programs aimed at developing new resistant cultivars.